John l



@einen tatrs atrnt @ffice Letters Patent No. 76,471, dated April T,1868.

IMPROVEMENT IN SAW-MILLS.'

fgehltle referat tu im tlpse tfittctt ditant mit uniting gmt tt tigesmite.

TO ALL WHOM IT MAY CONCERN:

Be it known that I, JOHN L. KNOWLTON, of Philadelphia, in thecounty'ol`Philadelphia, and State of Pennsylvania, have invented a new andimproved Sawing-Machine; and I do hereby declare that the following is afull, clear, and exact description thereof, which will enable thoseskilled in the art to makeand use the same, reference being had to theaccompanying drawings, forming part of this specification.

This invention relates to a new and improved machine for sawing timberin straight, curved, or bevelled form, and is an improvement on amachine for the same purpose, patented by me, October 20,1863, andreissued September 12, 1865.

The `object of the present invention is to render the machine betteradapted for the sawing of crooked or curved timber, such ns is used forship-building, and while effecting this result, to obtain simplicity inconstruc tion, a greater facility otv manipulation, and a lesscumbersome machine than usual. In the accompanying sheet of drawings-Figure 1 isa front sectional View of my invention, taken in the line :cx, tig. 2.

'Figure 2, a horizontal section ofthe same, taken in the-line y y, g. 1.i y K Figure 3, a detached vertical section of a part pertaining to thesame, taken in the line z z, iig. 4.

Figure 4, a. horizontal section oi" Eg. 3,V taken in theline e a.

Similar letters of reference indicate corresponding parts.

A represents a. frame, which supports a horizontal bed, B, said framehaving two uprights, d d, to which horizontal bars b 6 are attached,onev at some distance above the other, as shown clearly ing. 1.

To these bars b b' there is permanently bolted, or otherwise secured,asegment, G, of Wood or metal; cast iron lwill probably be used. Thissegment is provided or cast yvith a flange, c, which extends out from itat i right angles, and concentric with it; and in the exterior surfaceot' this tiange there is made a. groove, d, to receive friction-rollers,which are secured to axsegmcnt, D, to admit of D moving freely on C, andsecuring the former to the latter. Y

The exterior of the segment D is toothed, to receive a screw, E, throughtheV medium of'which the segment C is turned. v

The segment D has saw-guides F F attached to it, in line with eachother, anc in a positiony radial with the segment, said guides havingslides G G fitted within them, to which the ends ofthe saw I-I areattached.-

The slides G Gr are secured tothe inner ends of levers I I, by means ofconnecting-links z" t" which serve, as the saw is operated, to keep thesides ofthe slides parallel with the sides of the guide'sF, in order toprevent the former from being twisted or crampedin the guides. Thefulcrafof the levers are on the segment D, and

the outer ends of the levers are connected by a rod, J, the ends work inswivel-nuts g, lin the outer ends ofthe levers.

It will be seen from the above description that, by turning the rodJ,the saw H may be strained or kept at a proper degree of tension at alltimes. This will lie-fully understood by referring to g. 1.- 'A

The advantage of this arrangement consists in the dispensing Withthecomparatively heavy and cumberd sonic saw-sash, used in my originalmachine, and admitting of the saw being more readily strained thanhitherto. This is an important feature ofthe invention,l as iteconomize's in the construction of the machine, and reduces jars andconcussione, and consequent wear and tear.

of which are provided with screw-threads, to

The sawII works through a slit or hole in the hole in the hed B, and thesegments C and D admit of timlv bers being turned to any given anglerelatively with the saw, and also of very crooked timber being sawed, asthe ends of thc segments are so placed that the open 4space aX betweentheir ends is over the bed B. This is also an important feature ot' theinvention, ,as the original machine has its saw-gate attached to a platewhich forms a complete circle, and this plate worked on a guide, whichalso forms a complete circle. i

In the original machine,l therefore, a. stick of timber cannot be turnedon the bed B, back of the plane in which the segment C is placed, norcan a stick of timber be conveniently sawed which is quite crooked, astimber for the knees'ot` vessels, for insta-nce. By my improvement astick of timber, in being sawed, maybe turned around nearly in an entirecircle in a horizontal plane, and to facilitate this adjustment of thetimbers, I use annular ways I for the carriages or trucks to Work ormove on. A portion of these Ways is shown in fig. 2

By means of these annular ways, therefore,iand the open space a ,kthesawingot` crooked timber, more especially ship-timber, is greatlyfacilitated.

J represents the feed-wheels by which the timber is fed to the saw, andK is the pressure-roller above it.v

The feed-wheels` are rotated froma horizontal shaft, L, by means ofbevel-gears 71. and an upright shaft, z', two feed-wheels'JX JX beingused, and placed on -a shaft', j, (see fig-4.) This shaftj has itsbearings in a yoke, M, attached to a sleeve, N, which-is iitted loosely.on the upright shaft z', so that it may turn freely thereon. The lowerpart of this sleeve has a toothednvheel, k, upon it, into which a rack,Z, gears, said rack being itted in suitable guides, so that it may slidefreely'therein. By adjusting or moving this rack l, the feed-wheelsJ JXvmay be turned so as to coincide with the direction designed tobe giventhe timber in its movement towards the saw. Thisit will beseen, isessential, as the Wheels JX J feed the timber to the saw, and it isowing to the position of said wheels'(the planes in which they rotaterelatively with'the saw) that the vfeed-movement of the timber has theproper direction given it. V i v By the arrangement of the feed-wheelsas above described, they may be adjusted with the greatest facility bythe operator.

The above-described improvements render my original patented machine farmore desirable and valuable than hitherto, :is-they not only `facilitatethe manipulation of the machine while in operation, but render the samecapable of performing Work which cannot be conveniently done with theoriginal one.

I claim as new, and desire to secure by Letters Patentl Y 1. The guidesF, slides G, connecting-links z" z", pivoted levers I I, andcennec'ting-rod'J, in combination with the smv H, all arranged andoperating as described, 'for the purpose specified. b

2. The construction and arrangement of the segments C D, the formerhaving the opening 1X for the purpose, substantially as described. 1

3. The rack Z, and pinion K, in combination with the sleeve N, yoke M,and feed-rollers JX, as herein described, for the purpose specified.

' JOHN L. KNOWLTON.

Witnesses:

`CrniRLns B.'MITGHELL,

WM. F. HELMS.

